학술논문
Photostimulated electron transfer and its action on paramagnetism of [Sp.sub.3]Cr([C.sub.2]O.sub.4).sub.3 single crystals
Document Type
Report
Source
Journal of Experimental and Theoretical Physics. Oct, 2009, Vol. 109 Issue 4, p667, 9 p.
Subject
Language
English
ISSN
1063-7761
Abstract
The effect of irradiation by ultraviolet light on the effective magnetic moment of a paramagnetic single crystal based on photochrome spiropyran (Sp) and chromium oxalates [Sp.sub.3]Cr([C.sub.2]O.sub.4).sub.3 molecules is detected. It is shown that the deviation of the temperature dependence of the magnetic moment from the Curie law is caused not by the exchange interaction, but by electron redistribution between Cr.sup.3+ and Cr.sup.4+ ions and spiropyran molecules Sp.sup.0 and Sp.sup.+. Analysis of the angular dependence of EPR spectra makes it possible to determine the contribution of Cr.sup.3+ ions to the magnetic properties of the crystals and to determine the crystal field parameters D = 0.619 cm.sup.-1 and E = 0.024 cm.sup.-1. Irradiation of hydrated samples by ultraviolet light leads to intensity redistribution of EPR lines attributed to Cr.sup.3+ and Sp.sup.0. Thermally stimulated paramagnetism of triplet states of spiropyran ions Sp.sup.+ and the SpI salt is observed.